Method and apparatus for severing and capturing polyps

ABSTRACT

A method and apparatus for managing polyps by which an elongated tubular member generally positionable within the working channel of an endoscopic device. The tubular member carries a selectively extendable severing device and capturing device at its distal end. Control apparatus at the proximal end of the tubular member enables a physician to extend and retract the severing and capturing devices. The physician retracts the capturing device to grasp the portion of the polyp to be severed and retracts the severing device to sever the polyp. The capturing device retains the severed portion of the polyp for removal with the tubular member. In one embodiment the capturing device includes an injection needle.

This is a division of application Ser. No. 08/421,409, filed Apr. 13,1995, now U.S. Pat. No. 5,846,248 which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to surgical apparatus and methods for polypmanagement and more particularly to such apparatus and methods forsevering and capturing polyps.

2. Description of Related Art

The treatment of polyps and other similar growths in a patient hasimproved greatly within the last several decades. Polyps are generallycollected for histopathological evaluation to determine if they arecancerous. Initially the primary method of treating polyps was majorsurgery. Now polypectomy procedures are based upon the insertion of asurgical catheter through the working channel of an endoscope.Polypectomy procedures have essentially replaced surgical proceduresexcept when polypectomy procedures are deemed unsuitable, such as whenthe polyp or polyps to be removed are relatively planar in nature. Asused in this application, an endoscope includes endoscopic or othersimilar device that is inserted into a patient and that includes aworking channel for receiving a surgical catheter or the like and aviewing channel for viewing the interior of a vessel.

The following United States Letters Patent disclose surgical apparatusfor polyp management procedures:

U.S. Pat. No. 5,122,147 (1992) Sewell, Jr.

U.S. Pat. No. 4,326,530 (1982) Fleury, Jr.

Sewell, Jr. discloses several embodiments of a polyp marking device andmethod of using them. FIG. 4 illustrates three generally concentricloops extending from the distal end of the housing. Spacing memberscontact each loop thereby to position the loops along radially inner,outer and underneath paths. The inner loop 20 has one end fixed to thehousing and rachets onto a polyp proximate its base by retraction of asecond end extending distally through the housing. The outer loop 23retracts to grasp the polyp proximate its free end. An intermediatecutting loop has one end fixed in the housing and severs the polyp byretraction of a second end extending through the housing. The inner loop20 remains attached to the base of the severed polyp.

In another embodiment disclosed by Sewell, Jr. retraction of a cuttingloop 21 severs an inner loop 20 from a housing. After such retraction, aforceps device is inserted through the distal end of the housing.Manipulation of the forceps device enables a physician to capture thesevered portion of the polyp. Other embodiments disclosed by Sewell, Jr.disclose clamping devices or jaws having one or more cutting edges forsevering a polyp whereby the jaws close to return the severed portion ofthe polyp. Sewell, Jr. avoids the use of an electric current forcauterizing the severed base by applying a hemostatic agent to the baseof the polyp from the inner loop.

Fleury, Jr. discloses a surgical instrument for removing cellular tissuefrom body cavities. The instrument includes a proximal handle and adistally extending tubular member. A cable passes through the tubularmember and includes a self-expanding loop or snare at its distal end.Extension and retraction of the cable enables the loop to enlarge andencompass a polyp and then to contract and sever the polyp. The loopconducts rf electrical current to cauterize the stump of the severedpolyp. However, the catheter of Fleury, Jr. does not provide apparatusassociated with the instrument itself for capturing the severed portionof the polyp. Rather Fleury, Jr. suggests that other suitable means suchas suction associated with a colonscope equipment (i.e., an endoscopicdevice) captures the severed portion.

Another type of know surgical catheter for; preforming polypectomyprocedures includes a loop or snare disposed at the distal end of thecatheter. A basket or net connects to the loop along its defined arc. Inuse the basket overlies the portion of a polyp to be severed by theloop. Thus, upon severing of the polyp the basket captures the severedportion.

The advantages of such prior art polypectomy procedures in contrast tomajor surgery are numerous. The advantages generally include reductionsin the time and trauma of the operation itself, the time of recovery ofthe patient, the risk of infection and other problems associated withmajor surgery. Thus, a surgical catheter device of the prior artgenerally includes a tubular member extensible through the workingchannel of an endoscopic device with a cutting loop positioned at thedistal end of the tubular member and may include a mechanism forcauterizing the base of a severed polyp.

However, prior art polypectomy devices sometimes are unsuitable fortreating certain polyps and are cumbersome and often extend the durationof a procedure unnecessarily.

Some embodiments disclosed by Sewell, Jr., for example, require the useof a separate forceps instrument used in conjunction with the disclosedinstrument to retrieve the severed polyp. Generally, Sewell, Jr.discloses a device which requires multiple control wires, three wires inthe case of the embodiment of FIG. 4. Furthermore, Sewell, Jr. leavesthe inner loop within the body of the patient so that it must beretrieved or otherwise passed from the patient's body.

The device disclosed by Fleury, Jr. also has limited usefulness becauseit does not include any apparatus for grasping the severed portion.Although some endoscopic devices use suction to extract tissue, thesuction, at acceptable levels, is frequently insufficient to hold asevered polyp at the end of the device. Using suction also requirespositioning the distal end of the endoscope proximate the polyp. This isnot always a simple task. It frequently requires a high degree of skilland dexterity. Should the polyp not be held, it is often difficult toretrieve the severed polyp. Using a forceps device to retrieve suchsevered portion usually requires the removal of the surgical catheterfrom the working channel of the endoscope device and insertion of theforceps device. The snare and basket arrangements offer the possibilityof retrieving several polyps without removing the apparatus from apatient. However, the weight of the basket depending from the snaretends to deflect the snare and the distal end of the surgicalinstrument. Consequently it can be difficult to maneuver the snare overa selected polyp. The loops of the basket overlying the snare also canimpede snare closure and severance of a selected polyp. Moreover, themovement of the basket loops along the snare tends to dull the snare andmakes the severing more difficult. The baskets, being metallic, cancontact the snare and bypass current used for cauterizing the severedstump of the polyp. Also, in the case where multiple polyps arecollected there is no means to adequately associate the particularpolyps collected with the location from which such polyps were taken.

The prior art taken collectively, thus fails to provide an easily usedand simply constructed surgical apparatus for effectively and reliablysevering and capturing polyps of diverse shapes and sizes. There is nosuggestion of a method and apparatus for efficiently and effectivelycapturing a polyp or severing and capturing successive polyps in areliable manner and, additionally, being able to associate the positionfrom which such polyps were taken with particular polyps. Further, theprior art devices which require repeated removal and insertion to take aplurality of polyps generally also require repeated removal andinsertion of the endoscope, because polyps frequently are larger thanthe working channel of such endoscopes. Thus, the repeated insertion andremoval increases the time for such polypectomy procedures andassociated trauma to the patient.

SUMMARY

Therefore, it is an object of the present invention to provide asurgical apparatus for effectively and reliably severing and capturing apolyp.

Another object of this invention is to provide a surgical apparatus thatis simple to manufacture and use and that efficiently and effectivelycaptures and severs a polyp.

Still another object of this invention is to provide a method formanaging polyps that enables a physician to efficiently and effectivelyremove polyps from a patient.

Yet another object of this invention is to provide a surgical apparatushaving a holding device and a severing device positioned at a distal endof the apparatus that are independent of each other.

Yet still another object of this invention is to provide a surgicalapparatus having a control mechanism for concurrent extension andretraction of a holding device and a severing device positioned at adistal end of the apparatus.

Still yet another object of this invention is to provide a method forsevering and capturing a polyp that includes the step of positivelyholding the polyp prior to severing such that the severed portion of thepolyp is captured.

Yet a further object of this invention is to provide a method andapparatus for enlarging a polyp to promote severing and for capturing apolyp.

Still yet a further object of this invention is to provide a method andapparatus for successive severing and capturing of polyps within apatient prior to removal of the apparatus.

A further object of this invention is to provide a method and apparatusfor retaining severed and captured polyps in an order corresponding tothe order of such severing and capturing.

According to one aspect of this invention apparatus for severing andretaining a polyp includes an axially extending catheter with a distalend that can be positioned proximate a polyp. A self-expansible severingand capturing device is extensible from the distal end in an expandedform and is retractable into the catheter in a compacted form. Actuationof a control device at a proximal end of the catheter externally of thepatient enables extension and retraction of the severing and capturingdevice relative to the distal end of the catheter thereby to enablepolyp removal.

According to another aspect of this invention a surgical instrument,adapted for use in the working channel of an endoscopic device and forcapturing and severing a portion of a polyp includes an elongatedtubular member extending proximally from a distal end and a snarecarried by the tubular member for encompassing and severing a polyp.Selective extension of a holding device carried by the tubular memberindependently of the snare holds the polyp proximate its free end sothat upon severing of the polyp the holding device retains the severedportion of the polyp.

According to yet another aspect of this invention a surgical instrumentfor severing and capturing a polyp includes an elongated tubular memberproximally extending from a distal end and adapted to extend through theworking channel of an endoscopic device with a viewing channel. Thetubular member supports a snare for extension in an enlarged conditionand retraction in a compact condition relative to the distal end.Control apparatus enables a physician to selectively extend and retractthe snare. A capturing device connects with the control apparatus forextension and retraction with the snare so that upon retraction thecapturing device grasps and retains a portion of the polyp severed bythe snare.

According to a further aspect of this invention a method for managingpolyps in a patient includes locating a catheter proximate a selectedpolyp. Extension of a self-expansive severing device from the catheterencompasses the polyp proximate its base. Extension of a holding devicefrom the distal end of the catheter upon maneuvering engages the polypproximate a free end thereof. Retracting the severing device into thecatheter severs the polyp proximate the polyp's base; the holding deviceretains the severed portion that includes the free end.

According to yet a further aspect of this invention a method formanaging polyps in a patient includes locating a catheter proximate aselect polyp. Extension and orientation of a severing and holding devicefrom the catheter includes encompassing the polyp with a severingportion of the device and a holding portion of the device engaging thepolyp proximate a free end thereof. Retraction of the severing andholding device severs the polyp with the holding portion of the deviceretaining a separate portion including the free end of the selectedpolyp.

BRIEF DESCRIPTION OF THE DRAWINGS

The appended claims particularly point out and distinctly claim thesubject matter of this invention. The various objects, advantages andnovel features of this invention will be more fully apparent from areading of the following detailed description in conjunction with theaccompanying drawings in which like reference numerals refer to likeparts, and in which:

FIG. 1 is a plan view of a surgical instrument constructed in accordancewith this invention having a severing and holding device at a distal endportion for location within a patient proximate a polyp;

FIG. 2 is a enlarged side elevation of a distal end portion of FIG. 1;

FIG. 3 is a enlarged plan view of the distal end portion of FIG. 1 withthe severing and holding device in partially retracted position;

FIG. 4 is a enlarged plan view of the distal end portion of FIG. 1 withthe severing and holding device in a retracted position with the polypsevered at is base and the severed portion retained by the holdingdevice;

FIG. 5 is an enlarged plan view of the distal end portion of anothersurgical instrument in accordance with this invention;

FIG. 6 is an enlarged side elevation of the distal end portion of theembodiment of FIG. 5;

FIG. 7 is an enlarged plan view similar to FIG. 5 of the distal endportion of another surgical instrument in accordance with thisinvention;

FIG. 8 is a side elevation of the distal end portion of FIG. 7;

FIG. 9 is a plan view of the embodiment of FIG. 7 with the severing andholding device in a partially retracted position;

FIG. 10 is a plan view of the embodiment of FIG. 7 with a severingportion of the severing and holding device retracted into the tubularmember;

FIG. 11 is a plan view of the embodiment of FIG. 7 with the distalportion of a holding portion of the severing and holding deviceretracted proximate the distal end of the tubular member;

FIG. 11A is a view of the embodiment of FIG. 7 similar to FIG. 11 withthe distal portion of the holding portion having a plurality of severedpolyps retained therein;

FIG. 12 is a side elevation of a yet another surgical instrumentconstructed in accordance with this invention with a severing device anda holding device in an extended position relative to a tubular member;

FIG. 13 is a cross-section of the tubular member of FIG. 12 taken alongthe line 13--13;

FIG. 14 is a cross-section of the handle portion of FIG. taken along theline 14--14;

FIG. 15 is a cross-section of the handle portion of FIG. taken along theline 15--15;

FIG. 16 is a side elevation of the distal portion of FIG. with theholding device and the severing device partially retracted into thetubular member;

FIG. 17 is similar to FIG. 16 with the severing device retracted and theholding device retracted proximate the distal of the tubular member;

FIG. 18 is a perspective view of a distal portion of yet still anothersurgical instrument in accordance with this invention;

FIG. 19 is a perspective view of a distal portion of a further surgicalinstrument in accordance with this invention;

FIG. 19A is the view of FIG. 19 with a plurality of severed polypsretained on the retaining portion of the device with the severingportion retracted.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

As depicted in FIG. 1, apparatus 10 for managing polyps according tothis invention includes a radially flexible, axial stiff elongatedcatheter or tubular member 11 extending proximally from a distal end 12with a severing device 13 and a capturing device 14 extensible from andretractable relative to the distal end 12. The severing device 13 andthe capturing device 14 connect at their proximal ends to a cable 15that extends through the catheter 11 to a handle 16. The cable 15 inthis embodiment connects to a slide member 17 suitably supported in thehandle 16, although alternatively the cable can be fixed to the handle16 with the slide member 17 connecting to the tubular member 11. Thoseskilled in the art will appreciate that displacement of the slide member17 enables a user to selectively control the distal extension andproximal retraction of the severing device and the capturing devicerelative to the distal end 12.

FIGS. 1 through 4 illustrate the use of the present invention which ispreferably used with a known endoscopic device having a working channeland a viewing channel. The severing device 13 in this embodiment isformed as a snare 24, and the capturing device 14 comprises forceps 25with distally extending legs 26 secured to the snare extending from thedistal end of the cable 15. Each of the legs 26 includes an inwardlyextending portion 27 at its free or distal end.

In use, a physician inserts the distal end 12 through the workingchannel of an endoscope and uses the viewing channel to position thedistal end 12 proximate a polyp 28. Once the severing and capturingdevices 13 and 14 are extended relative to the distal end 12, thephysician maneuvers the severing device 13 to encompass the polyp 28proximate its base 30. The proper maneuvering of the severing devicealso positions the capturing device 14 as illustrated in FIGS. 1 and 2.The physician then retracts the cable 15 relative to the distal end. 12by moving the slide member 17 (FIG. 1) from its distal position towardthe position 17' to displace the severing and capturing device 13 and 14into the tubular member 11. As depicted in FIG. 3, retraction of thesevering device 13 and the capturing device 14 causes the severingdevice 13 to close and sever a portion 31 of the polyp 28 andconcurrently to urge the severed portion 31 into engagement between thelegs 26. Thus, after the severing of the polyp 28 the severed portion 31is retained by the capturing device 14 so that it can be removed fromthe patient as the tubular member 11 is withdrawn.

FIGS. 5 and 6 depict an alternative embodiment including a severingdevice 13 and a capturing device 14. In this case the capturing device14 comprises two leg members 40 extending from opposed central portionsof the snare 24 to define a plane intersecting the plane of the snare24. Retraction of the severing device 13 and the capturing device 14,once positioned so that the severing device 13 encompasses a polyp 28with the capturing device 14 disposed proximate the free end of thepolyp 28, urges the leg members 40 toward each other so that the portion31 of the polyp 27 to be severed from the base 30 is grasped or grippedby the leg members 40 enabling retention and removal of the polyp fromthe patient. Each of the leg members 40 may also include a radiallyinwardly extending projection 41 proximate free ends 42 to capture thesevered portion 31 in a positive fashion.

FIGS. 7 through 11 depict another embodiment of this invention thatincludes a severing device 13 and a capturing device 14 that are formedas a snare 24 and a collar or clip 50, respectively. The clip 50 has aclosed distal end 51 with legs 52 extending proximally therefrom. Thelegs 52 attach to opposed central portions of the snare 24 so that theclip lies outside the plane defined by the snare 24. In using thisembodiment, a physician positions the snare 24 to encompass a polyp 28proximate its base and the clip 50 opposite the base 30 of the polyp 28.Retraction of the snare 24 into the tubular member 11, as depicted inFIGS. 9 and 10, severs the polyp 28 and urges the severed portion 31into the clip 51. Further retraction, as depicted in FIG. 11 urges thesevered portion 31 into a secure position against the distal end of theclip 51. It will be appreciated by those skilled in the art thatproviding a collar or clip of sufficient distal extension for receivinga plurality of polyps will enable the removal of such polyps prior toremoval of the apparatus 10 from the patient's lumen 23.

The embodiment of FIG. 7 thus enables the grasping and retention of aplurality of polyps. The plurality of retained polyps will be arrangedsequentially with the distal most polyp corresponding to the firstsample sequentially with the proximal most polyp being the last polypcaptured. Thus, the polyps will be stacked in the clip in the order ofsevering. Specifically each polyp is urged distally in the clip 50, asthe cable 15 is retracted to bring the distal end 51 of the clip 50proximate the distal end 12 of the tubular member 11. Thus, asillustrated in FIG. 11A where severed polyps 31 and polyps 31A and 31Bhave been sequentially severed and retained, the polyps 31, 31A and 31Bwould reside between the legs 52 in a secure position at the distal end51 of the clip 50.

Use of this embodiment enables the physician to associate the polypswith the position from which it was severed. Thus, for example, only aportion of the plurality of the captured polyps are found to becancerous, this ability to determine the location can be used todetermine what segments of the lumen 23 need to be surgically removed.Use of this embodiment also eliminates the waste of time involved inremoving from the patient's lumen 23 the tubular member 11 and generallyan associate endoscope through which the tubular member is extended toretrieve a severed polyp after each severing and capturing operation.

FIG. 12 depicts still another apparatus 60 according to this inventionthat comprises a radially flexible, axial stiff elongated catheter ortubular member 61 having a distal end 62 from which a severing device 63and a capturing device 64 extend and retract. The severing device 63 andthe capturing device 64 connect at their proximal ends to a cable 65 anda hollow cable or hypotube 66, respectively, that extend proximalthrough lumens 67 and 68 (FIG. 13) in the tubular member 61 to a twopart handle 69. The severing device 64 comprises an expansible snare 70,the capturing device 63, a forceps-needle combination 71 that extendsthrough a sheath 72 and that includes a hollow needle 71A that conveysfluid into a polyp.

Referring now to FIGS. 12, 14 and 15, a physician controls the operationof the forceps-needle combination 71 and the snare 70 from the handle 69at a proximal end of the apparatus. A first portion 73 of the handle 69(FIG. 14) supports a slider 74 that attaches to the cable 65. Distaldisplacement of the slider 74 enables the physician to extend the snare70 from the distal end 62 as depicted in FIG. 12; proximal displacementof the slider 74 retracts the snare 70 as depicted in FIG. 17.

The handle 69 also includes an electrical plug 83 that suitably connectswith the cable 65 to provide mono-polar cauterization of a base of apolyp severed by the snare 70. Alternatively, the electrical plug 83 canbe eliminated in cases not needing cauterization orhypotube 66 cansuitably connect plug 84 with the forceps needle combination 71 toenable bi-polar cauterization.

A second portion 75 (FIG. 15) of the handle 69 includes a slider 76disposed in a slidable housing 77 supported in an outer housing 78 asdepicted in cross-section in FIG. 15. The sheath 72 connects with theslider 76. Displacement of the slider 76 connected to sheath 72,relative to the slidable housing 77 connected to hypotube 66 and thusconnected to capturing device 64, displaces the sheath 72 relative tothe forceps-needle combination 71, thus enabling the extension, asdepicted in FIG. 12, and retraction as depicted FIG. 16. The hypotube 66secures to a proximal end 80 of the slidable housing 77 so thatdisplacement of the slidable housing 77 and the slider 76 togetherdisplaces the forceps needle combination 71 and the sheath 72 relativeto the distal end 62 of the tubular member 61 (FIGS. 12 and 17). Aproximal end 81 of the hypotube 66 in this embodiment includes aninjection hub 82.

In operating the apparatus 60, the physician preferably positions thetubular member 61 to extend from the working channel of an endoscopicdevice 100 previously inserted in a patient. The physician manipulatesthe slider 74 and the slidable housing 77 and the slider 76 to extendthe snare 70 and the forceps-needle combination 71 over a polyp 85, asdepicted in FIG. 12. If the polyp 85 is a relatively small, flat polypof a type that is usually difficult to sever and/or retrieve by priorart apparatus, the physician positions the snare 70 to encompass a base86 of the polyp 85 and pierces the polyp 85 with the needle 71A betweenthe base 86 and a free end 87 of the polyp 85 to inject a suitable fluid(e.g., a saline solution or sclerotherapy agents) into the polyp 85 fromthe injection hub 82 to expand and swell the polyp 85. The physicianthen closes forceps legs 71B of the forceps needle combination 71 tocapture the now swollen polyp 85 by distal displacement of the sheath 72relative to the forceps legs 71B (FIG. 16). Retraction of the snare 70severs the polyp 85 so that the forceps-needle combination 71 retainsthe severed portion including the free end 87. Retracting the slidablehousing 77 and distal displacing the slider 76, as shown in FIG. 17,moves the forceps-needle combination 71 into close proximity of thedistal end 62.

FIGS. 18 and 19 depict distal portions of the apparatus 60 withalternative capturing devices 64A and 64B, respectively. The embodimentof FIG. 18 includes only a forceps device 89 with extending legs 90.Those skilled in the art will understand that in this case the hypotube66 can be solid and that the sheath 22 can, alternatively, be omitted sothat the legs 90 expand and contract upon extension and retractionrelative to the distal end 62 of the tubular member 61. Additionally,the hypotube 66 can be connected to a slider suitably mounted in ahandle (not shown) similarly to the slider 74 of FIG. 12 with theslidable housing 77 of FIG. 12 also omitted.

The capturing device 64 of the embodiment of FIG. 19 includes only aneedle 91 without any forceps device. The needle 91 operatessubstantially the same as the needle 71A of the embodiment of FIG. 12.That is, it connects with a proximal slidable member (not shown) toextend and retract the needle 91 and includes a means for enabling afluid to be injected through the needle 91. The needle 91 furtherincludes one or more barbs 92 or other similar surface features formedthereon proximate its distal end. The barbs 92 tend to retard withdrawalof the needle 91 from the polyp 85. Consequently, the polyp 85 tends toremain on the needle 91.

Thus, after severing the polyp 85 by the snare 70, the severed portionpolyp 85 including the free end 87 can be removed by withdrawal of theelongated tubular member 61. This embodiment also enables the collectionof additional polyps by successively extending and positioning the snare70 and needle 91 and then retracting the snare 70, as discussed above.That is to collect an additional selected polyp, such as the polyp 85after collecting polyps 85B and 85A, respectively, the user positionsthe distal end of the device proximate the polyp 85 and extends thesnare 70 to encompass the polyp and the needle 91 to pierce the polyp.Upon piercing the selected polyp 85, previously severed polyps retainedon the needle 91 are urged proximally along the needle 91. The user canthen inject the polyp 85 with a suitable solution, if desired, prior tosevering the polyp 85 by retracting the snare 70. Once severed, thepolyp 85 would be retained on the needle 91 as described above. Thus, asillustrated in FIG. 19A, a plurality of polyps severed and retained inthe sequential order of the polyps 85B, 85A, 85 are retained proximatethe distal end of the needle 91.

In summary, there have been described various embodiments of devices forsevering and capturing polyps without prior art surgical intervention.Specifically, these devices include a catheter or like elongated tubularmember having one or more lumens therein adapted for extending throughthe working channel of an endoscopic device having a viewing channel.Severing and capturing devices connect with control apparatus at theproximal end of the catheter to enable extension and retraction of thesevering and capturing device relative to the distal end of thecatheter. This structure enables a physician to selectively grasp apolyp, sever a portion of the polyp from its base and withdraw the polypfrom the patient. The severing device typically includes a snare. Thecapturing device may comprise a closed end clip, legs arranged in aforceps-like configuration, a barbed needle, or combination thereof. Aneedle can also allow a physician to inject fluid into a polyp therebyto enlarge the polyp and facilitate its severing and its removal.

Those skilled in the art will further appreciate that the describeddevices can be relatively easily constructed according to known methodsand relatively easily used by physicians familiar with prior artdevices. However, this invention provides physicians with devices thatare more versatile in dealing with polyps and that are relatively easilyused while also providing greater surety in retention of the portions ofpolyps that are severed as compared with the prior art devices. Thisinvention has been disclosed in terms of certain embodiments. It will beapparent that many modifications can be made to the disclosed apparatuswithout departing from the invention. Therefore, it is the intent of theappended claims to cover all such variations and modifications as comewithin the true spirit and scope of this invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:
 1. Apparatus for severing and retrieving a polypfor withdrawal from a patient comprising:a catheter extending between adistal end tip and a proximal end, for positioning proximate a polyp; aself-expansible severing and capturing device for retrieving a polyp,said severing and capturing device being extensible from said distal endof said catheter in an expanded form and retractable into said distalend in a compacted form; and a control device at the proximal end ofsaid catheter for selectively extending and retracting said severing andcapturing device relative to said distal end of said catheter, whereinsaid severing and capturing device includes, in said expanded form, awire forming a complete loop portion lying in a first plane to receive apolyp therethrough and a substantially planar collar portion fixed toand disposed distally from said complete loop portion and lying in asecond plane such that retraction of said wire urges the closing of saidcomplete loop portion to sever a polyp extending therethrough and urgesthe severed polyp into said collar portion.
 2. Apparatus for severingand retrieving a polyp as recited in claim 1 wherein said collar portionis elongated to receive therein and retain a plurality of severedpolyps.
 3. Apparatus for severing and retrieving a polyp as recited inclaim 1 wherein said control device includes a slider at a proximal endof said catheter and an axially stiff, laterally flexible cableextending through said catheter, said cable connecting said slider andsaid severing and capturing device such that displacement of said sliderurges like displacement of said severing and capturing device.
 4. Asurgical instrument for severing and capturing a polyp, the instrumentcomprising:an elongated tubular member having a distal end, a snareforming a complete loop portion, said snare for extension in a firstplane in an enlarged condition from and retraction in a compactcondition into said distal end of said tubular member, a control devicefor selectively extending said snare relative to said distal end so asto enable positioning said snare to encompass a polyp and forselectively retracting said snare relative to said distal end so as tosever such polyp, and a substantially planar capturing device fixed toand disposed distally from said snare and connected to said controldevice such that said capturing device is extended with said snare insubstantially a second plane wherein upon extension, said snare definesa first plane and a portion of said capturing device defines a secondplane substantially parallel with said first plane and upon retractionof said snare by said control device said capturing device grasps thepolyp outside the first plane so that upon severing of the polyp by saidsnare said capturing device retains the severed portion of the polyp. 5.An instrument as recited in claim 4 wherein said control device includesa cable supporting said snare at a distal end thereof.
 6. An instrumentas recited in claim 5 further comprising a handle supporting a proximalend of said tubular member wherein said control device includes anactuator slidably disposed in said handle for enabling displacementalong the axis of said tubular member to selectively extend and retractsaid snare relative to said distal end of said tubular member.
 7. Aninstrument as recited in claim 5 wherein said capturing device comprisesa closed distal end clip structure with proximally extending spaced legssecured to said snare intermediate a distal end of said snare and saidcable.
 8. An instrument as recited in claim 7 wherein each of said legscomprising a first generally planar extending portion proximate saidclosed distal end of said clip structure and a second generallyvertically extending portion remote from said closed distal end of saidclip structure such that said first generally planar extending portionof said clip structure defines the second plane that is generallyparallel to said first plane.
 9. A method for managing polyps in apatient comprising the steps of:inserting a catheter within the patientwith a distal end disposed proximate a selected polyp; extending in afirst plane a self-expansive severing device forming a complete loopfrom the catheter and positioning the severing device so as to encompassthe selected polyp proximate a base of the selected polyp; extending asubstantially planar holding device in a second plane from the distalend of the catheter said holding device being fixed to said severingdevice, said second plane being substantially parallel to said firstplane; positioning and manipulating the holding device so as to engagethe selected polyp proximate a free end of the selected polyp; andretracting the severing device into the catheter to sever the selectedpolyp proximate the base such that the holding device retains a severedportion including the free end of the selected polyp, wherein said stepof retracting the severing device also retracts the holding device suchthat the engagement of the holding device with the portion of theselected polyp is promoted thereby.
 10. A method for managing polyps ina patient comprising the steps of:A) inserting a catheter within thepatient with a distal end disposed proximate a selected polyp; B)extending a severing and holding device with a severing portion forminga complete loop and with a substantially planar holding portion fixed tothe severing portion and lying in a plane offset from the severingportion; C) orienting the severing and holding device with the severingportion of the severing and holding device encompassing the polyp andthe holding portion engaging the polyp proximate a free end thereof; andD) retracting the severing portion to sever the polyp with the holdingportion retaining a severed portion including the free end of theselected polyp.
 11. A method as recited in claim 10 furthercomprising:E) removing the catheter from the patient to retrieve theretained polyp.
 12. A method as recited in claim 11 wherein said step ofB) through D) are repeated so as to retain a plurality of polyps priorto step E).
 13. A method as recited in claim 12 wherein said step ofretracting retains polyps in an order corresponding to the order inwhich each polyp is retained thereby upon repetition of said steps B)through D).